Two decades ago, the pathologist G.B.D. Scott began comparing human diseases to naturally occurring diseases in animals with the expectation that this might lead to a greater understanding of both. This early interest soon became focused on non-human primates - man's closest evolutionary relatives. This text provides a comprehensive, well-balanced review of the pathology of simian primates and of the relevant recent literature. The book thoroughly covers all organ systems as well as the pathology of some common inflammatory and parasitic diseases and cancer. The comparative approach used, in which the pathological processes found in humans are contrasted to those of primates, provides a deeper appreciation of the conditions encountered in primates. This work will be of particular interest to those concerned with primate welfare or comparative pathology.